Cod sursa(job #2277735)

Utilizator savulescustefanSavulescu Stefan savulescustefan Data 6 noiembrie 2018 19:23:22
Problema Heavy Path Decomposition Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 3.88 kb
#include <cstdio>
#include <vector>
using namespace std;
vector <int> m2[100004],m3[100004],v[100004];
int n,m,i,j,x,y,c,z,q,w,nr,nr3,poz1,poz2,Max,k,aux,lg[200008],t[100004],a[100004],r[200008][19],s[100004],l[100004],poz[100004],le[100004],pr[100004];
bool b[100004];
void query (int st, int dr, int poz1, int poz2, int nod)
{
    if ((st>=poz1) && (dr<=poz2))
    {
        if (Max<m3[i][nod])
            Max=m3[i][nod];
        return;
    }
    if (((st+dr)/2)>=poz1)
        query(st,(st+dr)/2,poz1,poz2,nod*2);
    if ((((st+dr)/2)+1)<=poz2)
        query(((st+dr)/2)+1,dr,poz1,poz2,(nod*2)+1);
}
void up (int st, int dr, int nod)
{
    if (st==dr)
    {
        m3[i][nod]=x;
        return;
    }
    if (((st+dr)/2)>=poz1)
        up(st,(st+dr)/2,nod*2);
    else
        up(((st+dr)/2)+1,dr,nod*2+1);
    if (m3[i][nod*2]>m3[i][(nod*2)+1])
        m3[i][nod]=m3[i][nod*2];
    else
        m3[i][nod]=m3[i][(nod*2)+1];
    return;
}
void g (int x)
{
    int i,k,Max,poz1;
    bool ok;
    ok=true;
    b[x]=true;
    k=v[x].size();
    k--;
    Max=0;
    poz1=0;
    for (i=0;i<=k;i++)
    {
        if (b[v[x][i]]==false)
        {
            le[v[x][i]]=le[x]+1;
            r[++nr3][0]=v[x][i];
            pr[v[x][i]]=nr3;
            g(v[x][i]);
            r[++nr3][0]=x;
            if (s[v[x][i]]>Max)
            {
                Max=s[v[x][i]];
                poz1=v[x][i];
            }
            ok=false;
        }
    }
    if (ok==true)
    {
        s[x]=1;
        nr++;
        l[x]=nr;
        poz[x]=1;
        m2[nr].push_back(x);
        return;
    }
    l[x]=l[poz1];
    poz[x]=poz[poz1]+1;
    m2[l[x]].push_back(x);
    s[x]=s[poz1]+1;
    for (i=0;i<=k;i++)
    {
        if ((v[x][i]!=poz1) && (le[x]<le[v[x][i]]))
            t[l[v[x][i]]]=x;
    }
    return;
}
void f (int x,int y)
{
    while (l[x]!=l[y])
    {
        z=l[y];
        i=z;
        poz1=poz[y]-1;
        k=m2[z].size();
        k--;
        query(0,k,poz1,k,1);
        y=t[l[y]];
    }
    z=l[x];
    i=z;
    poz1=poz[x]-1;
    poz2=poz[y]-1;
    k=m2[z].size();
    k--;
    query(0,k,poz2,poz1,1);
}
int main()
{
    freopen ("heavypath.in","r",stdin);
    freopen ("heavypath.out","w",stdout);
    scanf ("%d %d", &n, &m);
    for (i=1;i<=n;i++)
        scanf ("%d", &a[i]);
    for (i=1;i<=(n-1);i++)
    {
        scanf ("%d %d", &x, &y);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    le[1]=0;
    r[1][0]=1;
    nr3=1;
    pr[1]=1;
    g(1);
    lg[1]=0;
    for (i=2;i<=nr3;i++)
        lg[i]=lg[i/2]+1;
    for (i=1;(1<<i)<=nr3;i++)
        for (j=1;j<=(nr3-(1<<i));j++)
        {
            if (le[r[j][i-1]]<le[r[j+(1<<(i-1))][i-1]])
                r[j][i]=r[j][i-1];
            else
                r[j][i]=r[j+(1<<(i-1))][i-1];
        }
    for (i=1;i<=nr;i++)
    {
        k=m2[i].size();
        k*=3;
        for (j=1;j<=k;j++)
            m3[i].push_back(-1);
        k/=3;
        k--;
        for (j=0;j<=k;j++)
        {
            x=a[m2[i][j]];
            poz1=j;
            up(0,k,1);
        }
    }
    for (j=1;j<=m;j++)
    {
        scanf ("%d %d %d", &c, &x, &y);
        if (c==1)
        {
            z=pr[x];
            q=pr[y];
            if (z>q)
            {
                aux=z;
                z=q;
                q=aux;
            }
            w=lg[q-z+1];
            if (le[r[z][w]]<le[r[q-(1<<w)+1][w]])
                w=r[z][w];
            else
                w=r[q-(1<<w)+1][w];
            Max=-1;
            f(w,x);
            f(w,y);
            printf ("%d\n", Max);
        }
        else
        {
            z=l[x];
            poz1=poz[x]-1;
            i=z;
            x=y;
            k=m2[z].size();
            k--;
            up(0,k,poz1);
        }
    }
    return 0;
}